My wife reported our little Sunbeam coffee maker was no longer working. It wasn’t pumping water etc. Here we go again I thought. Another unrepairable appliance!
We have had this Sunbeam for about 5 years and it made OK coffee, as long as you gave it plenty of time to heat up. There was also a lingering problem with puddles of water under it but I always assumed (that word again) that the problem was related to the removable plastic water tank on the back.
Totally ignoring the warnings “no user serviceable components inside” I pulled the back off and immediately noticed rust on several components –
Now that wasn’t cool. Rust doesn’t happen the moment something gets wet and this looked long term. I could understand rust on lower components getting there from a leaking valve but the bracket holding the pump (blue component on right) was rusty. Could see anything spectacularly wrong so I plugged it in and watched. Once I started the coffee cycle, the problem was obvious almost straight away. The union on the hose above the pump sprayed water over most of the innards of the machine. Why it hadn’t tripped a earth leakage breaker was unknown.
That accounted for the leaks and the rust. Once the coffee cycle starts the pump starts a rhythmic thumping and this had loosened the union.
20 seconds with a spanner, 2 minutes to put the back on and its as good as new. Made my day as for once, I didn’t have to “Chuck it out” Yay!
Well the Arduino project has grown again. I think Arduino must be Italian for spontaneous growth! Here a picture of the latest state.
It now sports a few additions.
– Freetronics Ethershield – It has an integrated prototyping area which holds a “Dead on RTC – DS3234” which is running (as is the Ethershield) on a SPI bus. I had minor moment when, while testing, either the ES or the RTC ran (not both). A bit of digging and the ES needs SPI MODE 0 while the RTC needs MODE 3. The RTC now means that my wife can turn the system off when it rains. Previously you had to turn it back on around the time you started watering but now its agnostic about the startup time.
– Freetronics LCD shield. The buttons on the shield are used to manually start the watering cycle if required.
The stuff which was on the Sparkfun prototype area has all moved to the breadboard including the run LED and the water on LED as well as the driver for the relay. I ran out of digital pins on the Arduino, the LCD uses 7, but the analog pins work fine.
Naturally, if you add ethernet to anything then a web server is required. You can check out the status of my watering system at http://watering.bluegumsoftware.com The other great use of an ethernet interface is you can sync the RTC to NTP on the *net. Its REALLY important that your watering is synced to UTC.
What next? I think a rain sensor is coming as well as the aforementioned connections to the staghorns. Biggest issue there is hiding the ugly black Irrigation pipes!.